Answer:
A dorsal root (sensory or afferent) and a ventral root (motor or efferent) originate from the medulla. They unite near the intervertebral foramen, forming the spinal nerve. The nerves emerge from the intervertebral foramen, dividing into ventral and dorsal ramus.
Explanation:
The nerve is a set of nerve fibers perceptible to the naked eye and wrapped in connective tissue. They are made up of roots, trunks and nerve branches (some of them come together and form plexuses).The spinal nerve originate from the spinal cord in the form of 31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal. They emerge from the spinal cord through two roots: dorsal roots, made up of sensory fibers that come from the sensory neurons of the spinal ganglion and that penetrate the spinal cord through the posterolateral and ventral root, made up of motor fibers, coming from the motor neurons of the anterior horn and visceral of the lateral horn of the gray matter of the spinal cord. This root exits the spinal cord through the anterolateral groove, then joins the posterior root to form the spinal nerve, which exits the vertebral canal through the corresponding intervertebral foramen.Each spinal nerve, after leaving the vertebral canal, emits two primary ramus: the dorsal ramus, contains somatic and visceral fibers that go to the skin and muscles of the back and the ventral ramus, which supplies the ventrolateral surface of the skin, body wall and extremities.
Answer:
<h2>
potassium</h2>
Explanation:
The heartbeats of the heart are controlled by the sinoatrial node also known as the pacemaker of the heart. The impulse is generated in the conducting cells of the pacemaker as a result of the movement of sodium, potassium and calcium ions.
The sodium channels allow the movement of sodium into the cell which depolarizes the membrane from -60mv to -40 mv. At this point, the calcium gated channels open which allow the entry of the calcium in the cell which depolarizes the cell up to +5mv.
At this point, the potassium channels open which allows the potassium ions to move out of the cell. This repolarizes the cell and hence the cycle again begins. Reducing the permeability of the potassium ions help generate the autorhythmicity due to repolarization and thus is the correct answer.
Answer:
Im sorry if i late but the answer i believe is C. if i wrong let me know!
Light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in a vacuum in one year.
While there is no authoritative decision on which year is used, the International Astronomical Union (IAU) recommends the Julian year.
A light-year is equal to 9,460,730,472,580.8 km (about 9.461 Pm; 5,878,625,373,183.61 statute miles; about 63,240 astronomical units or about 0.3066 parsecs.
The exact length of the light-year depends on the length of the reference year used in the calculation, and there is no wide consensus on the reference to be used.
The figures above are based on a reference year of exactly 365.25 days (each of exactly 86,400 SI seconds).
A few examples of distances for light to travel are: Reflected sunlight from the Moon's surface takes 1.3 seconds to travel the 4.04 × 10-8 light years to Earth.
It takes 8.3 minutes for light to travel from the Sun to the Earth (a distance of 1.58 × 10-5 light-years).
The most distant space probe, Voyager 1, was 13 light hours (only 1.5 × 10-3 light years) away from Earth in September 2004.
It took Voyager 27 years to cover that distance.
The nearest known star (other than the Sun), Proxima Centauri is 4.22 light years away.
The center of our galaxy, the Milky Way, is about 26,000 light years away.
